Work-clamp for buttonhole cutting and stitching machines.



No. 767,540. PATENTED AUG. 16, 1904.

E. B. ALLEN. WORK CLAMP FOR BUTTONHOLE CUTTING AND STITGHING MACHINES.

APPLIOATION FILED APR. 21. 1904.

NO MODEL.

2 SHEETS-SHEETL R P 3 Q N k! 3 Q N N Q.

RM" ,i "r a I Q i i jg i m GQIE-QJEE 5 7 i v a Q:

R T 5 5%. g 3: I

' coma PATENTED AUG. 16, 1904.

E. .13. ALLEN. WORK CLAMP FOR BUTTONHOLE CUTTING AND STITOHING MACHINES.

APPLICATION FILED APR. 21. 1904.

2 SHEETS-SHEET 2.

N0 MODEL.

UNITED STATES A Patented August 16, 1904.

PATENT OFFICE.

EDWARD B. ALLEN, OF ELIZABETH, NEW JERSEY, ASSIGNOR TO THE SINGER MANUFACTURING COMPANY, A CORPORATION OF NEW JERSEY.

WORK-CLAMP FOR BUTTONHOLE CUTTING AND STITCHING MACHINES.

SPECIFICATION forming part of LettersPatent No. 767,540, dated August 16, 1904.

2 Application filed April 21, 1904. Serial No. 204,160. (No model.)

To all whmn it may concern.-

Be it known that I, EDWARD B. ALLEN, a citi- Zen of the United States, residing at Elizabeth, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in VVork-Clamps for Buttonhole-Cutting and Stitching Machines,

of which the following is a specification, reference belng had therein to the accompanying drawings.

This invention has for its object to provide vance of the stitching it is important not only that the goods be held securely close to the needle-path for preventing the lifting of the cut edge of the buttonhole by the friction of the rising needle in the goods or the subsequent pull of the needle-thread under the action of the take-up to insure uniform laying and setting of the stitches throughout the buttonhole-stitching operation, but to prevent the relative movement and consequent abra sion of the out edges of the material farther from the needle-path, due to the same action of the needle and its thread, in order to prevent the fraying of such edges in advance of the stitching.

My present invention therefore consists, primarily, in the combination, with the primary workclamp, of an auxiliary workclamp comprising a presser-plate having a flat lower or operative face adapted to overlie the face of the material adjacent the knife and1 needle paths and provided with openings or apertures closely embracing said paths and means for maintaining the said presser-plate normally pressed upon the material and for holding the same in fixed longitudinal relation to the needle and knife paths. It also consists in certain other constructive features to be hereinafter described.

In the accompanying drawings, which represent the present invention as embodied in the buttonhole cutting and stitching machine forming the subject of my application filed herewith, Serial No. 204,159, Figure l is a side elevation of the machine with the bedplate partially in section. Fig. 2 is a plan, upon a larger scale,.of the forward portion of the bed-plate and the work-clamps applied thereto. Fig. 3 is a transverse section of the work-clamps on the line 3 3 of Fig. 2; and Figs. 4, 5, and 6 are perspective views, respectively, of the auxiliary preSser-plate and the bar to which it is pivotally attached, the presser-plate detached, (exposing its under side,) and the operative portion of the presserfoot of the primary upper clamp member.

The frame of the machine comprises the usual bed-plate 1 with bracket-arm 2, in the forward end of which is mounted the needlebar 3, whose needle 4 operates in conjunction with the shuttle 5 and the knife-bar 6, carrying the knife 7 and provided with a lug 8, connected by the link 9 with the forward end of a rock-lever 10, whose rear end is connected, by means of a stud 11, with the link 12, which is pivotally connected in turn with the forward end of the tilting lever 13, having at its rear end the angular slot 14, entered by a roller-stud 15, carried by an arm 16, projecting from the collar 17, secured by the clampscrew 18 adjustably upon the vertically-movable plunger-rod 19, which is carried by the vibrating stop-lever 20. pivoted to the bracketarm upon the center screws 21. The plunger 19, in conjunction with its spring 22, cooperates with the stop-motion cam 23 to successively retard and wholly arrest the motion of the main shaft 24, as usual, being set in inoperative relation to such cam by a lateral movement of the lever 20, whose lateral arm 25 is depressed by a treadle connection with-the rod 26 in opposition to the spring 27 and locked by suitable means in such position until automatically released for the stopping of the machine at the conclusion of the stitching operation. The tilting of the stop-lever 20 to withdraw the plunger 19 from engagement 7 with the cam 23 in starting the machine temporarily connects such plunger with the continuously-reclprocating actuator 24, carrying the spring-pressed pivoted latch-lever 25,

adapted to engage a suitable coupling-tooth The primary work-clamp of the present ma chine is similar in general constructive features and mode of operation to that of my prior patent, No. 738, 591,0f September 8, 1903,

the upper clamp member comprising the foot- 28 and intermediate plate 28, loosely connected, by means of screws 29, with the forward ends of-the bifurcated plate or lever 30, having the block 31 pivotally mounted, by means of the pin 32, upon the supporting-ears 33, carried by the longitudinally-sliding clamp-plate 34. This work-feeding slide-plate is mounted upon the transversely-moving work-shifting plate 35, deriving its lateral movements from a lever 36, fulcrumed in the swiveled block 37 and having one end adjustably connected to said plate by means of the screw 38 and carrying at its other end a roller-stud 39, entering a suitable cam-groove in the feed-cam 40.

The clamp-plate 34 receives its longitudinal feeding movements also from the feed-cam 40 by means of a bell-crank lever 41, one arm 'of which has the usual roller-stud 42 and to the other slotted arm of which is adjustably connected, by means of the screw 43, one end of a link 44, of which the opposite end is connected to the plate 34 by means of the pivotal stud 45.

'The work-shifting plate 35 carries the throatplate 46, having the transverse needle-opening 47 and longitudinalknife-slot 48, the throat-plate being surrounded by a depressed portion of the plate, forming a seat 35 for the opposite edges of the primary clamp member 28 under the action of the clamp-spring 50, which is formed with a longitudinal slot 49, having its sides fitted to the edges of said throat-plate.

formed with a flat under side slightly rounded ofi at the forward and rear ends to enable the material to slide readily in contact therewith and is provided with a transverse needle-opening 52, closely embracing the path of the needle in-its vertical and lateral movements, 1

and with a longitudinal slot 53, leading therefrom to the rear edge of said plate and closely embracing the'knife-path, as indicated in Fig.

3."-The opposite end of the foot has in its lower face a central longitudinal stitch-clearance groove '54 and a' downwardly-projecting rib 55 adjacent to the needle-opening 52, and

the under portion of such foot is also beveled oif at 56 adjacent the needle-opening from the central portion downward'toward the edge of the foot for purposes which will be later described. It will be observed that the foot 51 extends longitudinally in both directions from the needle-opening 52 in respect of the work-engaging edges of the primary clamping-foot 28, and is therefore adapted to overlie the material to be stitched both in advance and in the rear of'the needle in respect of the path of reciprocation of which it is maintained in fixed relation longitudinally at all stages of operation of the machine. The presserplate is provided in its middle portion with laterally-projecting lugs 57, by means of which and the pins 58 it is pivoted to the forked forward end portions of a presser bar or plate 59, which may be constructed in two relatively adjustable portions, as indicated in Figs. 1 and 2, and provided at the rear end with a sleeve 60, fitted loosely upon a lateral pin 61, projecting from the outer end of a enters a similar threaded hole in the upright portionof the bracket-arm 2 and is maintained rigidly in place by the lock-nut 64. The stud 62 is provided intermediate its ends with a clamp-socket having projecting cars 65, by means of which, in conjunction with the clampscrew 66, is clamped adjusta'bl-y in the desired axial position a cylindrical pin 67, having a flattened head 68, to which is rigidly secured, by means of fastening-screws 69, one end of a flat spring 70, of which the opposite end rests upon a bearing-pin 71, projecting from the upper side of the presser-bar 59.

The presser-bar 59 is positively held from free to act under the sole impulse of its spring The auxiliary presser plate or foot'51 is 70 for maintenance of its required degree of pressure upon the material.

In the operation of the machine, the stoplever 20 having been shifted to throw the upper end of the plunger 19 forwardly out of engagement with the stop-cam 23 to set the machine in motion, the initial rotation of the main shaft from which the cutter-actuator 24 derives its motion causes the cutter 7 to form the buttonhole-slit, after which the cutter mechanism is disconnected from the actuator and remains inoperative throughout the cycle of the machine. In the descent of the knife 7 the material is supported by 'the throatplate 46, and as the knife rises the tendency of the material to cling to it is overcome to a large extent by the presser-plate 51, which acts as a stripper to prevent such lifting of the material. The tendency of the material to become vertically displaced in the successive upward anddownward movements of the needle is similarly prevented to greater or less extent by the same members, the rib 55 of the presser-plate 51 entering the buttonhole-sl'it as the feeding continues and serving to slightly distend such slit for the passage of the needle and to deflect any loose threads left in the raw edges of the material in the cutting operation, so as to insure their being properly bound into their respective edges of the slit in the side-stitching operation.

.It will be observed that by cutting away the lower face of the presser-plate at the angle of the needle-slot 52 with the knife-slot 53, as at 56, the operative face of the presser- 2 plate is there reduced in such manner that as the stitching of the first side of the buttonhole proceeds under the forward feeding movement of the clamp in respect of the needle the materialis permitted to yield slightly adjacent to its edge under the action of its frictional resistance to the rise of the needle and the pull of the thread produced by the takeup in setting the stitches, whereby the purl, which has a tendency to lie intermediate the edge of the slit and the needle-punctures by reason of the winding of the needle-thread around the needle under the forward feeding action or the clamp, is drawn wholly to the edge of the slit, where itis laid'uniformly throughout the stitching of the first side of the buttonhole. While a similar effect would be produced by wholly removing the angle referred to for the entire thickness of the foot, it is desirable that this part should be beveled upwardly and inwardly to better support the goods and present its edge diagonally to the needle-thread at the stitch-setting stage to in sure uniformity of the operation. The cutaway part 56 at the forward edge of the needleopening 52 is unessential to the operation above described, but is preferable, especially. with less flexible materials, to insure the proper bending of the latter for the purpose described.

In the stitching of the second side of the buttonhole, when the Work is fed backwardly, whereby the needle-thread .is led straight from the needle-eye to the material, the natural tendency in the stitch-setting operation is to dispose the purl directly upon the edge of the material, and this tendency is assisted in this stage of the stitching operation, as well as in the stitching of the first side of the buttonhole, by the action of the presser-plate 51 inholding the material fiat and preventing its yielding under the actions of the rising needle 1 and the take-up. For thesake of clearness of illustration the sizes of the needle-opening 52 and knife-slot 53 are represented in the v drawings as somewhat exaggerated; but it,

is to be understood that: in practice these openings in the presser-plate 51 conform in:

shape and size more closely with the needle and knife paths, affording merely the necessary clearance for the effective operation of the needle and knife.

By reference to the drawings it will be observed that the lugs 57 project laterally through lateral openings i n the serrated workengaglngportions of the primary clamplngfoot 28, being pivoted by the pins 58 to the outer ends of the spaced arms or branches constituting the forward end portion of the presser-bar 59, which .embrace the primary clamping-foot 28. It. will thus be observed that while the presser-plate is pressed lightly upon material by the spring 70, mounted upon the head of the axially-adjustable pin 67, and thus-independently of the means for applying the clamping-pressure to the primary foot 28, the raising of theclamp-lever 30 by depression of its overhanging tail portion by the usual treadle connection engages the interlocking portions of the foot 28 with the lugs 57-0f the auxiliary foot 51, and thereby serves to simultaneously raise the latter for the insertion, removal, or shifting of the material.

From the foregoing description it will be observed that the work-holder embodying the present improvement consists of a primary clamp comprising the upper and lower members 28 and 34, movable both longitudinally and laterally, and the auxiliary clamp comprising the members 51 and 46, receiving a lateral shifting movement only at the ends of the longitudinal feeding movements of the primary clamp. By reason of the loose connections of the primary clamping-foot 28 with the plate or lever 30 and the auxiliary presser-bar 59 with its fixed pivotal supporting-pin 61 it is evident that the upper operative member of each of the clamps is ren dered capable of adapting itself to irregularities in the thickness of the material to be operated upon, and their effective hold upon the I work isthus assured.

It is evident, as before indicated, that the present improvement is susceptible of material variation in details of construction, and it is therefore to be understood that the invention is not limited to the specific constructive features and mode of operation herein shown and described.

The double work-clamp herein described, although designed particularly for that class of buttonhole-stitching machines in which the Work is fed longitudinally and shifted later.- ally in respect of the stitch-forming devices,- is evidently'well adapted for embodiment in that class of machines in which the longitudinal feeding movements or longitudinal feedingand lateral shifting movements are given to the stitch-forming devices.

Having thus set forth the nature of my invention, What Iclaim herein is- 1.. Ina, buttonhole-stitching machine, the

IIQ

Combination with stitch-forming devices comprising a vertically-reciprocating needle, a primary work-clamp, and means for producing relative longitudinal feeding movements be work-clamp and comprising a foot-piece with flat lower or operative face disposed intermediate the work-engaging portions of said primary clamp and provided with a transverse needle-opening closely embracing the path of reciprocation of the needle beyond which it extends longitudinally of said primary clamp in both directions, so as to overlie, adjacent the needle-path, the stitching produced by the stitch-forming devices, and means for maintaining said auxiliary work-clamp in fixed longitudinal relation to the path of reciprocation of said needle.

2. In a'buttonhole cutting and stitching machine, the combination with stitch-forming devices including a reciprocating needle, cutting mechanism comprising a reciprocating knife, a primary work-clamp, and means for producing relative longitudinal feeding movements between said stitch-forming devices and the primary workclamp,of an auxiliary workclamp operating in conjunction with said primary work-clamp and comprising a footpiece with flat lower or operative face disposed intermediate the work-engaging portions of said primary work-clamp and provided with a needle-opening and connected knife-slot closely embracingrespectively the paths of reciprocation of said needle and knife.

3. In a buttonhole-stitching machine, the combination wit-h stitch-forming devices, a laterally-movable work-shifting slide-plate and a longitudinally-movable work-feeding slideplate mounted thereon, of a primary clamping member mounted upon and cooperating with said work-feeding slide-plate, a throatplate carried by said laterally-movable slideplate, a laterally-disposed fixed pin I or support, an auxiliary clamping member having one end fitted slidablyto said fixed pin or support and the other end adapted to rest upon said throat-plate, and a sliding connection between said auxiliary clamping member and the longitudinally-movable slide-plate.

4:. In a buttonhole-stitching machine, the combination with stitch-forming devices and a primary work-clamp mounted to move both longitudinally and laterally in respect of the same, of an auxiliary work-clamp mounted independently of but adapted to operate in conjunction with said primary Work-clamp, and common clamp-opening means for simultaneously operating both clamps.

5. In a buttonhole-stitching machine, the combination with stitch-forming devices and a primary work-clamp mounted to move both longitudinally and laterally in respect of the same, of an auxiliary Work-clamp mounted.

independently of but adapted to operate in conjunction with said primary work-clamp, the feet of said clamps having interlocking parts, and means for opening one of said clamps.

6. In a buttonhole-stitching machine, the combination with stitch-forming devices and a primary spring-pressed work-clamp mounted to move both longitudinally and laterally in respect of the same, of an auxiliary workclamp comprising upper and lower members operating in conjunction with said primary work-clamp, and adjustable means for pressing together the component members of said auxiliary Work-clamp.

7. In a buttonhole-stitching machine, the combination with stitch-forming devices, a laterally-movable work-shifting slide-plate and a longitudinally-movable work-feeding slide-plate, of a primary spring-pressed clamping member mounted upon and cooperating with said work-feeding slide-plate, a throatplate carried by said laterally-movable slideplate, a fixed stud or support provided with a clamp-socket and a lateral pivotal pin, an auxiliary clamp member provided at one end with a sleeve loosely embracing said pivotal pin and at the other end with a foot-piece coopcrating with said throat-plate in clamping the work, an axially-adjustable pin having its shank fitted to said clamp-socket, and a spring having one end secured to the head of said axially-adjustable pin and its other end adapted to rest upon said auxiliary clamp member.

8. In a buttonhole cutting and stitching machine, the combination with cutting mechanism comprising a reciprocating knife, stitch forming devices including a reciprocating needle and a primary work-clamp movable both longitudinally and laterally in respect of said stitch-forming devices, of an auxiliary work-clamp movable laterally only in respect of said stitch-forming devices and comprising a foot-piece with fiat lower or operative face disposed intermediate the work-engaging portions of said primary clamp and provided with a needle-opening and connected knifeslot closely embracing respectively the paths of reciprocation of said needle and knife.

9. In a buttonhole cutting and stitching machine, the combination with cutting mechanism comprising a reciprocating knife, stitchforming devices including a reciprocating needle and a primary work-clamp movable both longitudinally and laterally in respect of said stitch-forming devices, of an auxiliary work-clamp movable laterally only in respect of said stitch-forming devices and comprising a foot-piece with flat lower or operative face disposed intermediate the work-engaging portions of said primary clamp and provided with a needle-opening and connected knifeslot closely embracing respectively the paths of reciprocation of said needle and knife, the lower face of said foot-piece being cut away mary work-clamp and a forked presser-bar embracing the primary clamping-foot and having pivotal connections With said footpiece extending through the lateral openings in the primary clamping-foot.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

' EDWARD B. ALLEN.

Witnesses:

ALFRED C. DARLING, HENRY J. MILLER. 

